Bucket T poor performance

[SSpev]

I have been unfocused again. I'm looking at the bucket again. This is an engine issue at part throttle. When cruising about 35 and slowly push the peddle it falls flat and does not recover unless I go further or back off. I think My secondary's are opening with out getting any fuel. At this point I don't think they should be opening. Or how about the power valve opening and causing a flood with out air. Carbs are 1850 with very heavy secondary springs. PV size
I now have a vacuum hose between the 2 carbs and a good signal to the advance.
Second thing. After its all warmed up, at idle it reves to about 1600. drop it in gear 500 and want to die. back to park it pick up to about 1000. the slow moves back to 1600. With out the vacuum it goes to 1300.
Any Ideas?

 

[409gang]

Usually when an engine stumbles while stepping on the throttle its a sign of a bad accelerator pump. With the engine off and the air cleaner removed hold the choke open and look down the carburetor while working the throttle, you should be able to see the pump squirting gas.

 

[SSpev]

Agree but that was the first thing I checked. I am not STEPPING on the throttle. That works fine. Its when I SLLOOWWLY push the throttle. New pump, arm just touches enough that any movement of the accelerator makes a squirt off idle. Squirter is a 25. I did get a cough out the carb once. I will change to 28. Also I have never saw this before. with air cleaners off, when going 20 mph and mash it, a fog of gas comes out of the carbs. I was thinking the air going over the engine is just pulling out the squirt?

 

[La Hot Rods]

What size hose did you use to balance the two half's of the intake.
The fuel you see about the carburetors is caused by the reversion that is a characteristic of this intake.

 

[SSpev]

just 3/8. Been thinking 1 inch phenolic spacer and add the largest vacuum port i could.

The fuel you see about the carburetors is caused by the reversion that is a characteristic of this intake.

The thought crossed my mind it could be some thin like that.

 

[La Hot Rods]

I would look into some shear plates to put under the carburetors.

 

[blkblk63ss]

Maybe I misunderstood your idle speed ,what is rpm at idle in park?

 

[SSpev]

1600 rpm idle with vac adv . drops to 500 in gear

I would look into some shear plates to put under the carburetors.

Thats a good idea! kinda expensive...

 

[blkblk63ss]

1600 rpm idle with vac adv . drops to 500 in gear

Thats a good idea! kinda expensive...

1600 rpm at idle ? Not knowing your engine components your idle is way too high.

 

[Don Jacks]

Are your power valves opening early due to reduced vacuum on each side?

 

[blkblk63ss]

He said 1850 carb's, not familiar with that but Holly comes up when I Google that number.. So what are they?

 

[Don Jacks]

They're the old single line,usually the vacuum secondary type carb.

 

[blkblk63ss]

Are secondary open,at idle ,hence the high idle? Another thought is he able to slow the idle down or not.

 

[SSpev]

Thanks for all the ideas. yes 1850 holley 600 vac sec. I wire the secondaries closed. no change. If they are open, That means I didn't look at the adjustment screw on them They could be, I'll be checking.

1600 rpm at idle ? Not knowing your engine components your idle is way too high.

Agree. If I slow it down much it won't run in gear.

Are your power valves opening early due to reduced vacuum on each side?

Thought of that Don. Just need to get smaller number valves. 6.5 was all I have.
Another thing is it likes A LOT of initial timing. I haven't check the marks for tdc. (piston stop, bar it over, mark bar it back mark, split the diff) I going to do it.

 

[SSpev]

Some thing else about the rpm drop at idle. It is a th400 with a real vega converter. I'm not a trans guy, I get the concept. could the converter be draging it down? I though t it would slip like the dickins.

 

[MRHP]

I think you may have the throttle plates open too far on the primaries, exposing too much of the transition slot. This will give high idle, drops lots when put in gear and such. The transition slot should be exposed .040-.060 when looking from underneath the carb. What intake do you have, and what timing are you using.

 

[blkblk63ss]

Yes get the timing checked. Just see if throttle plates are completely shut if you have them tied. Are you sure you have good s eal on base of carb ,correct gaskets ect.

 

[blkblk63ss]

On the convertor I would think if it were pulling motor down you could jack rear wheels on jack stands and drop in gear and if it still idled fast with rear wheels spinning, then step on brakes to stop wheels and then it drastically pulls motor down maybe that might be a problem ,don't know. On the motor have you ever sprayed choke cleaner and sprayed around base of carb and other vacuum sources? Do you have brake booster?

 

[IMBVSUR?]

With the idle needing to be at 1600, and then going down to 500 in gear, I would be looking at timing first. Just my 2 cents. What distributor do you have?

 

[Cayneman]

What type of engine is in this T Bucket?